Characteristics of the Main Varieties of Pungent Radish in Japan

Abstract

Ten out of 11 varieties of pungent radish in Japan had a higher content of isothiocyanate (pungent component) in the squeezed juice than Aokubii Daikon (general green-necked radish), and intense spiciness. The leaf shape, root shape, and root color varied, and no constant tendency was observed. However, because of their small size, low water content, high hardness, high brix value, and high sucrose content, they were all considered to belong to the northern radish. The content of isothiocyanate per squeezed juice of the test varieties was highest in ‘Kyoto Yakumi’ and also in Hamadaikon. A strong positive correlation was found between the dry matter ratio and amount of isothiocyanate, and varieties with a lower water content tended to have more isothiocyanate. There was a marked difference in the sugar composition among varieties, and the ratio of the sucrose content was particularly high in ‘Matsudate Sibori’ and Hamadaikon. It was suggested that the difference in sugar composition could be used as an index to show the relationships among varieties.